We complete our two-part interview with Ross Anderson, president of the Minnesota Building Performance Association. We discuss the myth that ventilation is a cure-all for roof and attic and ice dam issues, and discuss the real reason for these problems, which is attic air leaks (aka attic bypasses).
The gang also discusses turbine vents, turtle vents, and ridge vents, and works in a jab at Bill’s beloved 1.5-story homes, and Ross explains what it takes to cure ice dams on those homes for good.
You can get in touch with Ross through his company website, The Energy Network Worldwide.
Related link: Roof Vents: Problems and Solutions
The following is a transcription from an audio recording. Although the transcription is largely accurate, in some cases it may be slightly incomplete or contain minor inaccuracies due to inaudible passages or transcription errors.
Ross Anderson: The problem you have is, Well here’s two major problems, one is builders are afraid of it.
Tessa Murray: It’s different.
RA: And two, code officials have never seen it before so they get afraid.
Bill Oelrich: Welcome everybody, you’re listening to structure talk a Structure Tech presentation. My name is Bill Oelrich, along side Tessa Murray and Reuben Saltzman from Structure Tech. We were here again, today with Ross Anderson, we have bonus pod with Ross. And we thought it’d be just fun to dig into Ross’ head a little bit and talk about some real life experiences, things that he’s seen out in the field, problems that he’s solving for real life home owners, and what’s the algorithm of getting from the starting point to the finish line so people can live in a house that’s gonna be durable for years to come.
Reuben Saltzman: What brought this up, is just as we were walking in, Ross was telling me about how there was a house that I had inspected, and I guess there was some ice dam issues and he ended up going out to check it out. Well, take it away because you never even finished the story.
RA: Yeah, no, Structure Tech has a very excellent name in town, and so when people say, “I’ve had Structure Tech out and they told me X, Y, Z and I want a second opinion, on it” I always say “I’m sure it’s right, but I’d be happy to come out and check it out”, but I had somebody find me through our non-profit, the mbpa.us. Minnesota building performance Association, they reached out and asked if we would come out because they’ve had multiple contractors out giving them different answers to solve pretty simple ice dam issue. If you live in Minnesota, you have a home at all, you’ve had some sort of an ice dam issue at one point or another. Ice dams are a major issue. And last winter we had a massive problem with ice dams, and so this year has been crazy with the amount of calls we get on just opinions. And…
BO: This year, meaning the summer…
RA: Summer post-winter apocalypse we had last winter with the amount of snow. And so I’ve been out on quite a few projects to help as a consultant and put together a scope of work, but I had one funny call where the gentleman calls me up and then in the call said “I saw Reuben speak years ago, I actually had him come to my house and give me an opinion on what to do and I did not listen to him and I did what the roofer told me to do instead”, which happens quite often. I actually go out, I will tell the people how to repair… What they need to do. And I’m not an insulator, I’m not a roofer, I just understand how the concepts work. And so I put together a scope of work, they call in whoever roofer or insulator, and then the insulator says “No, no. You don’t need to do that. Just do it like this and pay me money, and I will see you later”.
RS: And what do roofers always like to do, what’s their same tack.
RA: More ventilation.
RS: More ventilation.
RA: More ventilation.
RS: Every time.
BO: More V.
RA: I still laugh. If you go… I don’t know how local this is, but if you go 169 North, right before Bass Lake Road, there’s four plexes on the side of the road that all have about eight whirlybird exhaust systems on top of it, that one of them would be plenty for the entire system, and they must have about 12 of them on there. So…
RS: I was staring at those today, as I was driving past them. I know exactly what you’re talking about.
RA: I’ve taken pictures of those.
RS: On the east-side of 169. Yeah.
BO: They don’t work?
RA: Oh they work great.
RS: Yeah, like one works really well for an attic. And eight might be more than you need.
TM: Whirlybirds are never a good idea, unless you’ve air-sealed your attic.
RS: Yes, let’s dig into that for a minute. Alright, a whirlybird. It’s that roof vent, or it’s the technical names of turban vent.
RA: Correct, turban ventured.
RS: And it’s… The idea is just a little bit of air movement, I think, as low as 5 miles per hour is gonna get those things moving and they’re gonna pull air out of your attic space and the whole idea is you’re gonna pull air in through the soffit vents, air’s gonna go in, it’s gonna pull in cold air, it’s gonna flush out the air in your attic and then air’s gonna leave, and then you’re never gonna have ice dams or condensation or frost or mold or any of that stuff. And it’s just a magic solution to your attic. Now, this assumes that your attic lid is perfectly air sealed, ’cause if it’s not, what are you gonna be pulling? You’re gonna be pulling outdoor air through the vents and you’re gonna be pulling indoor air, warm moist humid indoor air up into your attic space. So it’s not gonna fix your problem, it’s just gonna mean you’re pulling more air up there. Now, if you go and completely air seal your attic lid, then these things will work really well. However you perfectly air seal your attic lid…
TM: You don’t need them.
RS: You don’t need them! So, I’m not trying to knock them, I’m just saying people see these things as a magic bullet, they’re like, “This is gonna fix everything”. I think they’re great, they’re very nice. But you probably don’t need it, you’re probably okay with static roof vents. Alright. Ross, I feel like you wanna contradict me now.
RA: No, not at all. No. I 100% agree. They’re a ventilation strategy for an attic, you could use those, you can use a turtle vent as we would call them or they…
TM: Passive box vent.
RA: Box vent, roof vent.
BO: I like turtle vent.
TM: Turtle vents, yeah.
RA: We usually… Yeah, that’s our fun way to talk. When I talk roofer I talk turtle vents, right? And actually we’ve found, just lately, I’ve been doing a lot of research on ridge vents and how poorly they actually ventilate from the top. A side note, there is a really good YouTube video on a group that actually did a study on about 18 different versions of it and only one actually ventilated the roof system, which was crazy.
RS: Really. Which one?
TM: Was it Cor-a-vent?
RA: It’s a double Cor-a-vent. Yeah.
TM: Double Cor-a-vent.
RA: Yeah, it like a double… Yeah, so what they did was they basically just lit some little smokers inside the attic, little theatrical smoker, and went outside and just watched how much… They had cameras inside and outside and looked for how it ventilated in different temperatures and all of them, the attics were just smoky and almost no smoke came out except for the one, and I was blown away. It blew my mind.
TM: A lot of houses are built with Ridge vents, aren’t they? Continuous ridge vents.
RA: Yes. We actually just did… I was just part of a project that had a huge vault and they had put a ridge vent up on the top of the vault, and after they did that they started getting terrible ice dams on this vault. And so the fix was to come in and rip the roof off and put a bunch of spray foam in and do all these different things and so we went out and I said, “Well let’s just try taking the ridge vent off and throwing turtle vents back up there and see if that helps”. And they almost fixed it 100%.
BO: Wow. So how many thousands of dollars do you think you saved that particular home owner?
RA: Well, the spray foam alone is probably $5000 or $6000 they would have been putting in that attic.
RS: Oh man.
RA: And that was an option, it was, “Let’s just try this. Worst case scenario this will save you… ” our best case scenario, it’ll save you a lot of money, worst case scenario you just now changed out your vents and we’re gonna have to rip the roof off anyways and do the spray foam.
BO: I’ve often wondered when we get snow in Minnesota and it covers a ridge vent, if they don’t work when there’s no snow on the roof, they certainly can’t work when they’re six to eight inches of snow on the roof.
RS: And you know, just to expound on that, let’s just expand that to any vent, turtle vents, ridge vents, whatever. What happens when it’s covered in snow? People ask us that all the time.
RA: No, correct, I agree. But so here’s the deal, really what’s the goal of the attic? The goal is to keep the attic as cold as it can be, it’s as close to the outdoor temp as possible, and the indoor temp as close to the indoor temp as possible, and not to have the other affect each other. So if the outdoor temp is if you’re not leaking warm air into the attic and you’re still keeping that outside attic cooler, much cooler, or closer to the outside temperature, you’re still winning in that. Whether the ventilation is happening or not, we’ve now taken that attic space and kept it cool. That’s really the goal, right, is just to keep…
RS: Wait, wait, wait, you’re saying that ventilation is not a make or break thing for an attic space? Stop.
RA: It does help keep it cool, but it is definitely not the number one thing. The air sealing the floor of that attic is definitely the key.
BO: You can go on the forums this afternoon, Reuben, after you get out of here and tell all the home inspectors what you just learned.
RS: I’ve blogged about this. You know what, in this podcast episode I’ll have to remember to put a link to my blog post about ventilation and how it’s not all that it’s cracked up to be. Yeah it’s required, but that’s it. It’s usually used as an excuse for some other problem.
RA: I agree 100%. You just want that attic space to get as close to the outside temperature as possible. You’re gonna get melting from the sun anyways, from the topside down, it’s the management of that, right? Making sure that it’s managed properly.
BO: How often are you called to storey-and-a-half houses? Compared to other houses?
RA: I would say it’s a major call for sure. I mean storey-and-a-half houses are a nightmare in Minnesota just because they’re tough, they’re really tough.
TM: It’s okay, Bill. Don’t cry.
RA: They’re tough to manage.
RS: Now we did an episode on this, on one-and-a-half storey… Tessa and I, well, we don’t have anything nice to say about them, but we said stuff anyways, didn’t we?
RS: We weren’t supposed to.
TM: Well, they’re cute, but they have so many building performance problems with them.
RS: Yeah. And we started talking at the break, and I just cut us off, I said, “This is good pod, we gotta talk about this on the air.” Tessa and I are saying it’s impossible to fix these things, but you’re saying you do fix them. How do you fix them?
RA: Yeah, we fix them, but the one caveat to that, which Tessa did bring up was it’s not cheap. It’s not a cheap fix.
RS: So you tear the roof off, huh?
RA: Well, that’s one option, for sure.
RA: Or you double frame it.
TM: You can fix it if you wanna spend $30,000.
RS: It’s gonna be $30,000, yeah.
RA: 100%. And really in the end, the goal is most storey-and-a-half houses are not what people build brand new anymore, they don’t build the side walls and all the little side attics, they just don’t do it.
TM: All the dormers though. I mean there’s tons of dormers on some of these new construction houses and they…
RA: And they have nightmares with them.
TM: Exactly, but I mean you don’t see the storey-and-a-half but you see the vaults and you see the dormers.
TM: And side attics and…
RA: And they have nightmares with them and that’s why builders I work with, we put together a strategy ahead of time.
TM: Fire the architect. Just kidding.
BO: Why don’t you just build new with that solution that you talked about just earlier where… Put all the insulation at the… Just below the shingles and then everything inside of that is conditioned space?
BO: Put the overcoat on the beautiful story and a half house and don’t tear them down because they’re amazing structures.
RS: It’s just this little thing that Tessa’s alluding to between her thumb and forefinger.
Speaker 6: Money, money, money.
RA: Yeah, we are… The one thing…
RS: That’s why…
RA: The one thing I’m on a crusade now in Minnesota is to put exterior foam on the outside of all the buildings. And because nationally, this will be energy code going forward, not in Minnesota right now, but nationally that’s what they’re prescribing for our climate zone, I’m on a crusade to get builders to start thinking about it and manufactures have really built some really nice product, cost effective, that will work, and actually that are working for roofing applications and all different applications. The problem you have is, well here’s two major problems, one is builders are afraid of it, and two…
TM: It’s different.
RA: Code officials have never seen it before, so they get afraid of it. I’m literally working on a project right now with a new construction builder where we’re putting an R-6 exterior structural exterior foam on the outside of the whole building, and the code official, just every other turn, he just is freaking out about this project.
RS: That’s what I did the first time I saw it too, I’ll be honest. I was just like, “Wait a minute, what? Structural foam? No. No, this cannot be.”
TM: Would you say that the construction industry, and builders, and tradespeople, change is hard?
RA: Well of course it’s hard. Because you are a builder and what do builders have to do in Minnesota? They have to warranty the house for 10 years. So if something is going to break they don’t wanna be part of it. And do you wanna be the guinea pig?
TM: Right. No, and if something works you wanna keep doing it. And so it’s really hard to change how builders build houses.
RS: We’re still not on the metric system.
RA: No. My gosh. How easy would life be.
TM: I know.
RS: Oh my goodness.
BO: Tell me, what is structural foam? What does it look like from a building construction…
RA: So, it has to have… To get technical, it just has to have the racking strength that you need for any house. If you actually go South they will go as far as putting zero sheeting on the outside of a building, and just putting up what’s called a T-Ply, which is like a heavy duty cardboard as the exterior of the building. People get scared because they go, “Oh we don’t have plywood,” or “we don’t have something on the outside of the building,” but if that’s what you’re counting on to hold the building up, you’ve done it wrong. That’s not the structure of the house, that’s not the bones of how it’s built. So the structural foam has to be there for racking strength in a different structure, it’s not there to hold anything up. So it sounds… When I say structural it sounds like it’s heavy duty but it’s really just a foam that will bear the racking strength in the corners of the building that it’s needed.
BO: So when the wind blows or whatever, that’s what we’re talking about racking strength?
RA: Correct, correct. Side to side.
BO: Side to side. Okay.
RA: That’s right. And it does. And it works really well.
RA: It’s a really good product.
BO: So why is this such a good thing for our climate?
RA: Well, one of the things, to get super techy, is we get what’s called thermal break. We want a thermal break. So if you look… Here’s a fun thing. I have a infrared camera, if you ever play with a infrared camera you can go around your house and I can see all the exterior wall studs, and on a cold day I can actually find every screw that was put in by the sheet-rocker. Because of the thermal transference from the cold weather on the outside of the building to the inside. By adding that R-6, that foam on the outside of the building, it reduces that thermal transference and it keeps those walls quite a bit warmer so it’s a lot less taxing on what the heating and cooling system has to off-set.
RS: Do all those studs disappear with my IR camera when that happens?
RA: They get a lot less visible for sure.
RA: For sure. R-5 is kind of the minimum you see out there. There’s a structural foam that I like out there that’s an R-6. R-10, obviously the more foam on the outside of the building, the less insulation you need on the inside, the less moisture issues you have on the inside, the less mold issues you have on the inside. It’s actually… I mean, that would be the goal. As you move north, the cold-climate housing groups and everybody, they build with an R-10, R-20, R-30 on the outside.
RS: Just out of curiosity, what happens at all the joints on that stuff? Do you have joint treatment? I mean, do you use tape like a zip wall system or…
RS: Okay. So there is no additional water-resistant barrier?
RA: You do not need an additional barrier on the outside if you don’t want to. It will manage all the bulk water. I don’t like to bash a product but the difference between a structural foam over a zip wall is with zip wall it’s a painted on weather barrier and every time the nail punctures that barrier, you now have exposed OSB underneath there and at the tape joints, if water gets into that tape joint, you have exposed wood that can rot and do whatever. With foam, you’re taping and sealing, but anywhere where there’s a puncture all it’s getting is foam, so you’re never having molding or rotting or expansion…
RA: Or any issues you would have with an OSB that gets wet compared to a foam more on the outside of that.
RS: Sure. Sure. And for anybody, kind of glossed over it quick, just for our listeners, WRB is a water-resistant barrier and it’s just a big sheet that goes underneath the siding ’cause water is gonna get past any type of siding you put on your house. And you need some way of dealing with it once it does get past. So, you’re saying with this stuff you don’t need that extra sheet.
RA: Nope. Nope, that takes care of it.
RS: That’s nice.
RA: That takes care of that weather resistant barrier that you need on the outside of the home, it will manage the moisture, all the bulk water on the outside. So, it is, it’s a nice product. It’s the evolution, in my opinion, if I was building I would for sure do an exterior foam on my house.
BO: Very good. Reuben, you were just talking about blending new and old. Let’s expand on that right now.
RS: Yeah, we were talking about… And I bring this up during CE classes that I teach when we’re talking about how long a home inspection is gonna take and saying if it’s a bigger house it takes longer, if it’s older it takes longer. If one of the clients is an engineer it’s gonna take twice as long.
RS: All these…
RA: That is a truth if I’ve ever heard it spoke.
TM: Yes, yes.
RS: Yes, yes. And you know what’s funny? Every time I bring that up, there’s one person in the class who will start laughing hysterically and I’ll go, “Your spouse is an engineer, aren’t they?” And they go, “Yes!”
TM: Or they have a client who is an engineer they’re working with.
RS: Yes. But a huge one is when you have additions. Oh my goodness that makes things take so much longer. And people ask why and it’s like, “Well, ’cause you have a different heating system, you have new electrical that you need to run, maybe you got a sub-panel you had to add on, you have a different plumbing system, maybe they do testing on the vents.” I mean, everything.
TM: You have a different attic. Maybe a crawl space.
RS: Yes. It’s like a different house. Everything is different than everything else and it takes so much more time. And so, we were just thinking about this and thinking, “This is gotta be a nightmare from just a building performance standpoint, an energy standpoint, and comfort. What do you find in this department, Ross?”
RA: For sure. Oh, yeah. I have a great story. We did a… I went out because they were having huge mold issues in a brand new addition that was put on, and if you think about it, when you do any editions energy code and building code, whatever is the newest code, is now put into place for that addition, where the house might be built in the ’70s or the ’60s or the ’50s, so it’s under a different code and so you have two total different environments. So one’s ventilating one way naturally and the other one now is super tight. And if you have this bonus room and you’ve got plants in there and there, or you have your terrarium with your lizard or whatever it is and all of a sudden now this room is holding the moisture in way more than any of the rest of the house ever did, and it doesn’t have a ventilation system set up to run just that room or that addition, so now we have this huge mold terrarium in this room, and so now we had to add like a bath fan in a room that should never have a bath fan but it needs to be ventilated ’cause they shut the door in the room and it’s got its own heating system.
RA: And it gets crazy, and just not thinking through how the home… I mean, we always laugh. It’s unintended consequences. It’s stuff when builder A didn’t really understand how to meld old and new, we ripped everything apart, and now this looks good. Actually I have a really good builder that brings me in on remodels and will have me look at everything ahead of time and we’ll talk through some strategies and when they gut the house I go back in and we talk through strategies and then in the end we do testing to make sure that there’s nothing that we’ve screwed with. I mean, if you take an old house like this, what, 1890s house we’re in now and rip the walls apart ’cause you’re doing a big remodel and all of a sudden spray form everything tight. This home has never lived with tight walls and spray form. It will completely blow its mind, it will have no idea how to live and it will have mega unintended consequences. I see it all the time.
RS: It’s funny. I have a friend who bought this… It was more than a mansion. It was this home that took up basically like a city block in St. Paul.
RA: More than a mansion.
RS: It’s… Yeah. More than a mansion. I don’t know what you would have called it.
BO: Capital city. A great place to live.
RS: Yeah, that’s right, right on Capitol Hill or something. And the walls were not insulated, brick walls, not insulated. He knew this going into it and he really kicked around what to do with this, and he eventually just decided, “I ain’t touching it ’cause I don’t wanna do what you just talked about, ’cause I’m gonna change so much here, and I’m probably gonna end up with some new moisture problem that I’m gonna be chasing down forever and I know it’s gonna be a big energy penalty for me to leave it un-insulated. But I think that penalty is gonna be less than the penalty I’d pay for screwing up my moisture. And he just left it that way.
RA: Yep. No, actually that’s probably the smartest move he could have made. I’ve been out consulting with other gentlemen in my industry, Pat O’Malley, Pat and I both got called in on a project and they were going to spray foam all the walls, and I think that would have… We both agreed that that would have rotted out the walls and the brick would have fallen off the outside of the home over time, just because it didn’t get to breathe anymore.
BO: I’m really impressed with this contractor who’s got the foresight to bring in you as a building scientist and say, “Let’s talk about how this is gonna work together.” Wow, I mean, bless his heart or her heart for all the home builders out there. It feels like their project manager should be building scientists to head off these problems before they are all covered up, and now you can’t find them, or if you can find them you can’t fix them ’cause you can’t get to ’em.
RA: Yeah, man, you’re speaking to the choir. I try to promote us as another part of the team all the time for remodelers and builders. I just say, “We are not that expensive and we are way cheaper than the nightmare it’s gonna cost you to fix this in the end. So having us just walk through the project a couple of times during construction, just give you some heads up”. I really like to see the walls prior to dry wall, see what they did, see what their strategy was, how they sealed stuff up, if they decided to go with bat and poli, how that was sealed and how their different penetrations were taken care of, especially for older homes ’cause that now just totally changed the whole game on how that house lives.
RS: No, this is good stuff. I have people who regularly ask us if we can do that type of thing. And I always shy away from it. I say no, that’s not our bread and butter…
RA: For sure.
RS: But if I wanted to give your name out for this, just people will ask us a ball-park figure, what does it cost for something like this?
RA: I usually charge, if they want a report written at the stop, we usually charge about $150 for a stop out. Most of the time, if I’m gonna do a full consulting during the project, it’s $5-6-700 but…
RS: And how many stops is that?
RA: That’s like four or five. That’s me coming out and being on call for them, right?
RS: This is just an easy sell.
TM: We can’t compete.
RA: As funny as it sounds, it’s easy for me because I do it so much that I know what I’m looking for and I know what I’m seeing when I go in there. So it’s not like I’m there for six hours every stop, and it’s more I’m there for 20-30 minutes, take a bunch of pictures, write up a small report quickly and send it off to the builders so that they know what’s going on.
TM: And our team will be really happy about this.
TM: Joe, I’m just thinking about all the new construction and callbacks… Re-inspections he gets on new construction houses and his staff too.
RS: Well, and our office. We get a lot of requests for this kind of thing. We’ll be giving your name out for this. That’s good.
RA: I appreciate it. No, that’s great.
BO: Thank you Ross again for coming in and spending some time with us. We’re gonna wrap it up for today, but can you plug your website, the two websites, one more time?
RA: Yeah, no problem. So the non-profit group that I push heavily is the Minnesota Building Performance Association, which is mbpa.us. And then the company that does the new construction testing for builders, we’re The Energy Network Worldwide. You can just google us on that, for sure.
RA: You got it. You got it.
BO: Awesome. Thank you very much Ross. You’ve been listening to Structure Talk, a Structure Tech presentation. Thank you everyone and we’ll catch you next time.